<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
        let name = 'zzz'
        const obj = {
          x: 1,
          y: 2,
          [name]: 3,
        }

      //   console.log(['a', 'b'])

      //   const obj1 = {
      //     [0]: 'a',
      //     1: 'b',
      //     length: 2,
      //   }

      for (let key in obj) {
        console.log(key, obj[key]) // obj[key] ==> obj['x'] /obj['y']
      }
      //   console.log(obj1)
    </script>
  </body>
</html>
